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RC(8) FreeBSD System Manager's Manual RC(8)
NAMErc -- command scripts for auto-reboot and daemon startup
SYNOPSISrcrc.confrc.conf.localrc.d/rc.firewallrc.localrc.shutdownrc.subrDESCRIPTION
The rc utility is the command script which controls the automatic boot
process after being called by init(8). The rc.local script contains com-
mands which are pertinent only to a specific site. Typically, the
/usr/local/etc/rc.d/ mechanism is used instead of rc.local these days but
if you want to use rc.local, it is still supported. In this case, it
should source /etc/rc.conf and contain additional custom startup code for
your system. The best way to handle rc.local, however, is to separate it
out into rc.d/ style scripts and place them under /usr/local/etc/rc.d/.
The rc.conf file contains the global system configuration information
referenced by the startup scripts, while rc.conf.local contains the local
system configuration. See rc.conf(5) for more information.
The rc.d/ directories contain scripts which will be automatically exe-
cuted at boot time and shutdown time.
Operationofrc
1. If autobooting, set autoboot=yes and enable a flag (rc_fast=yes),
which prevents the rc.d/ scripts from performing the check for
already running processes (thus speeding up the boot process). This
rc_fast=yes speedup will not occur when rc is started up after exit-
ing the single-user shell.
2. Determine whether the system is booting diskless, and if so run the
/etc/rc.initdiskless script.
3. Source /etc/rc.subr to load various rc.subr(8) shell functions to
use.
4. Load the configuration files.
5. Determine if booting in a jail, and add ``nojail'' (no jails
allowed) or ``nojailvnet'' (only allow vnet-enabled jails) to the
list of KEYWORDS to skip in rcorder(8).
6. Invoke rcorder(8) to order the files in /etc/rc.d/ that do not have
a ``nostart'' KEYWORD (refer to rcorder(8)'s -s flag).
7. Call each script in turn using run_rc_script() (from rc.subr(8)),
which sets $1 to ``start'', and sources the script in a subshell.
If the script has a .sh suffix then it is sourced directly into the
current shell. Stop processing when the script that is the value of
the $early_late_divider has been run.
8. Re-run rcorder(8), this time including the scripts in the
$local_startup directories. Ignore everything up to the
$early_late_divider, then start executing the scripts as described
above.
Operationofrc.shutdown
1. Source /etc/rc.subr to load various rc.subr(8) shell functions to
use.
2. Load the configuration files.
3. Invoke rcorder(8) to order the files in /etc/rc.d/ and the
$local_startup directories that have a ``shutdown'' KEYWORD (refer
to rcorder(8)'s -k flag), reverse that order, and assign the result
to a variable.
4. Call each script in turn using run_rc_script() (from rc.subr(8)),
which sets $1 to ``stop'', and sources the script in a subshell. If
the script has a .sh suffix then it is sourced directly into the
current shell.
Contentsofrc.d/rc.d/ is located in /etc/rc.d/. The following file naming conventions
are currently used in rc.d/:
ALLUPPERCASE Scripts that are ``placeholders'' to ensure that cer-
tain operations are performed before others. In
order of startup, these are:
NETWORKING Ensure basic network services are run-
ning, including general network configu-
ration.
SERVERS Ensure basic services exist for services
that start early (such as named), because
they are required by DAEMON below.
DAEMON Check-point before all general purpose
daemons such as lpd and ntpd.
LOGIN Check-point before user login services
(inetd and sshd), as well as services
which might run commands as users (cron
and sendmail).
foo.sh Scripts that are to be sourced into the current shell
rather than a subshell have a .sh suffix. Extreme
care must be taken in using this, as the startup
sequence will terminate if the script does.
bar Scripts that are sourced in a subshell. The boot
does not stop if such a script terminates with a non-
zero status, but a script can stop the boot if neces-
sary by invoking the stop_boot() function (from
rc.subr(8)).
Each script should contain rcorder(8) keywords, especially an appropriate
``PROVIDE'' entry, and if necessary ``REQUIRE'' and ``BEFORE'' keywords.
Each script is expected to support at least the following arguments,
which are automatically supported if it uses the run_rc_command() func-
tion:
start Start the service. This should check that the service is
to be started as specified by rc.conf(5). Also checks if
the service is already running and refuses to start if it
is. This latter check is not performed by standard
FreeBSD scripts if the system is starting directly to
multi-user mode, to speed up the boot process. If
forcestart is given, ignore the rc.conf(5) check and start
anyway.
stop If the service is to be started as specified by
rc.conf(5), stop the service. This should check that the
service is running and complain if it is not. If
forcestop is given, ignore the rc.conf(5) check and
attempt to stop.
restart Perform a stop then a start.
status If the script starts a process (rather than performing a
one-off operation), show the status of the process. Oth-
erwise it is not necessary to support this argument.
Defaults to displaying the process ID of the program (if
running).
poll If the script starts a process (rather than performing a
one-off operation), wait for the command to exit. Other-
wise it is not necessary to support this argument.
rcvar Display which rc.conf(5) variables are used to control the
startup of the service (if any).
If a script must implement additional commands it can list them in the
extra_commands variable, and define their actions in a variable con-
structed from the command name (see the EXAMPLES section).
The following key points apply to old-style scripts in
/usr/local/etc/rc.d/:
+o Scripts are only executed if their basename(1) matches the shell
globbing pattern *.sh, and they are executable. Any other files or
directories present within the directory are silently ignored.
+o When a script is executed at boot time, it is passed the string
``start'' as its first and only argument. At shutdown time, it is
passed the string ``stop'' as its first and only argument. All rc.d/
scripts are expected to handle these arguments appropriately. If no
action needs to be taken at a given time (either boot time or shut-
down time), the script should exit successfully and without producing
an error message.
+o The scripts within each directory are executed in lexicographical
order. If a specific order is required, numbers may be used as a
prefix to the existing filenames, so for example 100.foo would be
executed before 200.bar; without the numeric prefixes the opposite
would be true.
+o The output from each script is traditionally a space character, fol-
lowed by the name of the software package being started or shut down,
without a trailing newline character (see the EXAMPLES section).
SCRIPTS OF INTEREST
When an automatic reboot is in progress, rc is invoked with the argument
autoboot. One of the scripts run from /etc/rc.d/ is /etc/rc.d/fsck.
This script runs fsck(8) with option -p and -F to ``preen'' all the disks
of minor inconsistencies resulting from the last system shutdown. If
this fails, then checks/repairs of serious inconsistencies caused by
hardware or software failure will be performed in the background at the
end of the booting process. If autoboot is not set, when going from sin-
gle-user to multi-user mode for example, the script does not do anything.
The /etc/rc.d/local script can execute scripts from multiple rc.d/ direc-
tories. The default location includes /usr/local/etc/rc.d/, but these
may be overridden with the local_startuprc.conf(5) variable.
The /etc/rc.d/serial script is used to set any special configurations for
serial devices.
The rc.firewall script is used to configure rules for the kernel based
firewall service. It has several possible options:
open will allow anyone in
client will try to protect just this machine
simple will try to protect a whole network
closed totally disables IP services except via lo0 interface
UNKNOWN disables the loading of firewall rules
filename will load the rules in the given filename (full path
required).
The /etc/rc.d/atm* scripts are used to configure ATM network interfaces.
The interfaces are configured in three passes. The first pass performs
the initial interface configuration. The second pass completes the
interface configuration and defines PVCs and permanent ATMARP entries.
The third pass starts any ATM daemons.
Most daemons, including network related daemons, have their own script in
/etc/rc.d/, which can be used to start, stop, and check the status of the
service.
Any architecture specific scripts, such as /etc/rc.d/apm for example,
specifically check that they are on that architecture before starting the
daemon.
Following tradition, all startup files reside in /etc.
FILES
/etc/rc
/etc/rc.conf
/etc/rc.conf.local
/etc/rc.d/
/etc/rc.firewall
/etc/rc.local
/etc/rc.shutdown
/etc/rc.subr
/var/run/dmesg.boot dmesg(8) results soon after the rc
process begins. Useful when dmesg(8)
buffer in the kernel no longer has this
information.
EXAMPLES
The following is a minimal rc.d/ style script. Most scripts require lit-
tle more than the following.
#!/bin/sh
#
# PROVIDE: foo
# REQUIRE: bar_service_required_to_precede_foo
. /etc/rc.subr
name="foo"
rcvar=`set_rcvar`
command="/usr/local/bin/foo"
load_rc_config $name
run_rc_command "$1"
Certain scripts may want to provide enhanced functionality. The user may
access this functionality through additional commands. The script may
list and define as many commands at it needs.
#!/bin/sh
#
# PROVIDE: foo
# REQUIRE: bar_service_required_to_precede_foo
# BEFORE: baz_service_requiring_foo_to_precede_it
. /etc/rc.subr
name="foo"
rcvar=`set_rcvar`
command="/usr/local/bin/foo"
extra_commands="nop hello"
hello_cmd="echo Hello World."
nop_cmd="do_nop"
do_nop()
{
echo "I do nothing."
}
load_rc_config $name
run_rc_command "$1"
As all processes are killed by init(8) at shutdown, the explicit kill(1)
is unnecessary, but is often included.
SEE ALSOkill(1), rc.conf(5), init(8), rcorder(8), rc.subr(8), reboot(8),
savecore(8)HISTORY
The rc utility appeared in 4.0BSD.
FreeBSD 10.1 November 17, 2009 FreeBSD 10.1